Distinct control mechanism of fine-grained sediments from Yellow River and Kyushu supply in the northern Okinawa Trough since the last glacial

© 2017. American Geophysical Union. All Rights Reserved. High-resolution multiproxy records, including clay minerals and Sr-Nd-Pb isotopes of the clay-sized silicate fraction of sediments from IODP Site U1429 in the northern Okinawa Trough, provide reliable evidence for distinct control mechanism on fine-grained sediments input from the Yellow River and the southern Japanese Islands to the northern Okinawa Trough since 34 ka BP. Provenance analysis indicates that the sediments were mainly derived from the Yellow River and the island of Kyushu. Since the last glacial, clay-sized sediments transported from the Yellow River to the study site were strongly influenced by sea-level fluctuation. During low sea-level stage (∼34–14 ka BP), the paleo-Yellow River mouth was positioned closer to the northern Okinawa Trough, favoring large fluvial discharge or even direct input of detrital sediments, which resulted about four times more flux of clay-sized sediments supply to the study area as during the relatively high sea-level stage (∼14–0 ka BP). The input of Kyushu-derived clay-sized sediments to the study site was mainly controlled by the Kuroshio Current and Tsushima Warm Current intensity, with increased input in phase with weakened Kuroshio Current/Tsushima Warm Current. Our study suggests that the Kuroshio Current was very likely flowed into the Okinawa Trough and thus influenced the fine-grained sediment transport in the area throughout the last glacial and deglacial. During ∼34–11 ka BP, the Kyushu clay-sized sediment input was mainly controlled by the Kuroshio Current. Since ∼11 ka BP, the occurrence of Tsushima Warm Current became important in influencing the Kyushu fine-grained sediment input to the northern Okinawa Trough

An 11-bp Insertion in Zea mays fatb Reduces the Palmitic Acid Content of Fatty Acids in Maize Grain

The ratio of saturated to unsaturated fatty acids in maize kernels strongly impacts human and livestock health, but is a complex trait that is difficult to select based on phenotype. Map-based cloning of quantitative trait loci (QTL) is a powerful but time-consuming method for the dissection of complex traits. Here, we combine linkage and association analyses to fine map QTL-Pal9, a QTL influencing levels of palmitic acid, an important class of saturated fatty acid. QTL-Pal9 was mapped to a 90-kb region, in which we identified a candidate gene, Zea mays fatb (Zmfatb), which encodes acyl-ACP thioesterase. An 11-bp insertion in the last exon of Zmfatb decreases palmitic acid content and concentration, leading to an optimization of the ratio of saturated to unsaturated fatty acids while having no effect on total oil content. We used three-dimensional structure analysis to explain the functional mechanism of the ZmFATB protein and confirmed the proposed model in vitro and in vivo. We measured the genetic effect of the functional site in 15 different genetic backgrounds and found a maximum change of 4.57 mg/g palmitic acid content, which accounts for ∼20–60% of the variation in the ratio of saturated to unsaturated fatty acids. A PCR-based marker for QTL-Pal9 was developed for marker-assisted selection of nutritionally healthier maize lines. The method presented here provides a new, efficient way to clone QTL, and the cloned palmitic acid QTL sheds lights on the genetic mechanism of oil biosynthesis and targeted maize molecular breeding

Bond Performance of Carbon Fiber-Reinforced Polymer Bar with Dual Functions of Reinforcement and Cathodic Protection for Reinforced Concrete Structures

The dual function of a carbon fiber-reinforced polymer (CFRP) bar working as reinforcement and impressed current cathodic protection (ICCP) anode for reinforced concrete structures has been proposed and researched in this paper. The ICCP tests with different current densities and polarization durations were first conducted for the concrete with high chloride content. After the ICCP application, pull out tests were then performed to investigate the bond behaviors of CFRP bars. Experimental results have shown the effectiveness of the new-type ICCP system with the CFRP bar as the anode on corrosion protection. The ICCP system provided electrons to the steel bar continuously and brought the potential of the steel bar down to the immunity region. Under the anodic polarization with a large current density of 100 mA/m2, the CFRP bar-concrete interface presented acidification and the chemical adhesion on the interface was decreased significantly. However, for cases in the experiment, the ICCP application had an insignificant influence on the ultimate bond strength

Effect of Drought Stress on Proteome of Maize Grain during Grain Filling

Based on isobaric tags for relative and absolute quantification (iTRAQ) technology, the proteome of grains of a maize cultivar Huangzao 4 under drought stress at grain filling stage was analyzed. The results show that under drought stress, 438 proteins were differentially expressed in the maize grains during grain filling. Among them, 200 were up-regulated and 238 were down-regulated. The gene ontology (GO) analysis shows that the biological processes in which differential proteins are more involved are cellular processes, metabolic processes and single biological processes; proteins in the cell component category are mainly distributed in cells, cell parts and organelles; and the proteins the molecular function category mainly possess catalytic activity and binding function. Differentially expressed proteins classified by COG are mainly involved in protein post-translational modification and transport, molecular chaperones, general functional genes, translation, ribosomal structure, biosynthesis, energy production and transformation, carbohydrate transport and metabolism, amino acid transport and metabolism, etc. The subcellular structure of the differentially expressed proteins is mainly located in the cell chloroplast and cytosol. The proportions are 35.01% and 30.21% respectively. KEGG metabolic pathway enrichment analysis shows that the differentially expressed proteins are mostly involved in antibiotic biosynthesis, microbial metabolism in different environments, and endoplasmic reticulum protein processing; the metabolic pathways with higher enrichment are the carbon fixation pathway and estrogen signaling pathway of prokaryotes; and the higher enrichment and greater significance are in the tricarboxylic acid cycle, carbon fixation of photosynthetic organisms and proteasome. The results of this study preliminarily reveal the adaptive mechanism of maize grains in response to drought stress during grain filling, providing a theoretical reference for maize drought-resistant molecular breeding

Drought Tolerance Identification and Eevluation of Maize during Flowering Stage in Guangxi

Total 20 maize varieties were subjected to drought stress at flowering stage, and then the relative water content, soluble sugar content, chlorophyll content, malondialdehyde (MDA) content and superoxide dismutase (SOD) activity in their leaves, as well as their yields were determined. The drought tolerance of the physiological and biochemical indexes was scored by five-level scoring method, and the drought tolerance index was calculated by the yield index to comprehensively evaluate the drought tolerance of maize during flowering stage. The results showed that the scores of drought tolerance of the maize varieties ranged from 1.929 3 to 5.659 5. Among them, the scores of Zhengda 619, Guidan 162 and Guidan 0810 were greater than 5.0, followed by Dika 008, Xianyu 30T60, Xianzhengda 901, Qingnong 68, South America No.1 and Wanchuan 1306 of which the scores were in the range of 4.0-5.0. The drought tolerance indexes were in the range of 0.410 4-1.096 3. Among the test maize varieties, the drought tolerance indexes of Guidan 0810, Pacific 99 and Zhengda 619 were greater than 1.0, and those of Xianyu 30T60, Dika 008 and South America No.1 were in the range of 0.9-1.0. The correlation between the two kinds of evaluation results was 0.588 7 and was extremely significant. The five-level scoring method and the drought tolerance index can be used simultaneously for the evaluation of drought tolerance of maize during flowering stage. The two aspects of evaluation results showed that Guidan 0810, Zhengda 619, Xianyu 30T60, Dika 008 and South America No.1 were drought-tolerant varieties, among which Guidan 0810 and Zhengda 619 were extremely highly drought-tolerant varieties

Genome-Wide Association Study of Haploid Male Fertility in Maize (Zea Mays L.)

Large-scale application of the doubled haploid (DH) technology by in vivo haploid induction has greatly improved the efficiency of maize breeding. While the haploid induction rate and the efficiency of identifying haploid plants have greatly improved in recent years, the low efficiency of doubling of haploid plants has remained and currently presents the main limitation to maize DH line production. In this study, we aimed to assess the available genetic variation for haploid male fertility (HMF), i.e., the production of fertile pollen on haploid plants, and to investigate the underlying genetic architecture. To this end, a diversity panel of 481 maize inbred lines was crossed with “Mo17” and “Zheng58,” the F1 hybrids subjected to haploid induction, and resulting haploid plants assessed for male fertility in two environments. Across both genetic backgrounds, we observed a large variation of HMF ranging from zero to ~60%, with a mean of 18%, and a heritability of 0.65. HMF was higher in the “Mo17” than in the “Zheng58” background and the correlation between both genetic backgrounds was 0.68. Genome-wide association mapping identified only few putative QTL that jointly explained 22.5% of the phenotypic variance. With the exception of one association explaining 11.77% of the phenotypic variance, all other putative QTL were of minor importance. A genome-wide prediction approach further corroborated the quantitative nature of HMF in maize. Analysis of the 14 significantly associated SNPs revealed several candidate genes. Collectively, our results illustrate the large variation of HMF that can be exploited for maize DH breeding. Owing to the apparent genetic complexity of this trait, this might best be achieved by rapid recurrent phenotypic selection coupled with marker-assisted selection for individual QTL

Effect of Foliar Application of Selenium Fertilizer on Yield, Selenium Content and Heavy Metal Contents of Waxy Maize

[Objectives] This study aimed to explore the effect of different concentrations of selenium fertilizer on the yield, selenium content and heavy metal contents of waxy maize, thereby providing reference for the scientific application of selenium fertilizer on waxy maize. [Methods] Different varieties of waxy maize (Guitiannuo 611, Guinuo 615 and Guiheinuo 609) were used as test materials. They were sprayed with different concentrations (0, 0.5, 1.0, 1.5 and 2.0 g/L) of water-soluble selenium fertilizer (Xinxibao) at the big flare stage, and the effect on the yield, selenium content and heavy metal contents of the waxy maize was analyzed. [Results] Foliar application of different concentrations of selenium fertilizer showed no significant effect on the yield and yield components of waxy maize. As the concentration of selenium fertilizer increased, the grain selenium content of different varieties of waxy maize increased. Among them, the increase of Guinuo 615 was the largest, of which the selenium content reached 0.265 mg/kg, 2.82 times that of the control (water). The cadmium and arsenic contents of different varieties of waxy maize decreased with the increase of the concentration of selenium fertilizer sprayed. Among the waxy maize varieties, the cadmium and arsenic contents of Guitiannuo 611 dropped the most significantly, up to 52.94% and 77.78%. In waxy maize, the correlation coefficients between selenium content and cadmium, arsenic contents were -0.550 9 (P<0.05) and -0.853 0 (P<0.01), respectively. [Conclusions] Spraying exogenous selenium fertilizer had no obvious effect on the yield of waxy maize. However, the increase of the concentration of exogenous selenium fertilizer could significantly increase the selenium content and reduce the cadmium and arsenic contents in grains of different varieties of waxy maize

Efficient All-Optical Plasmonic Modulators with Atomically Thin Van Der Waals Heterostructures

| openaire: EC/H2020/820423/EU//S2QUIP | openaire: EC/H2020/834742/EU//ATOPAll-optical modulators are attracting significant attention due to their intrinsic perspective on high-speed, low-loss, and broadband performance, which are promising to replace their electrical counterparts for future information communication technology. However, high-power consumption and large footprint remain obstacles for the prevailing nonlinear optical methods due to the weak photon–photon interaction. Here, efficient all-optical mid-infrared plasmonic waveguide and free-space modulators in atomically thin graphene-MoS2 heterostructures based on the ultrafast and efficient doping of graphene with the photogenerated carrier in the monolayer MoS2 are reported. Plasmonic modulation of 44 cm−1 is demonstrated by an LED with light intensity down to 0.15 mW cm−2, which is four orders of magnitude smaller than the prevailing graphene nonlinear all-optical modulators (≈103 mW cm−2). The ultrafast carrier transfer and recombination time of photogenerated carriers in the heterostructure may achieve ultrafast modulation of the graphene plasmon. The demonstration of the efficient all-optical mid-infrared plasmonic modulators, with chip-scale integrability and deep-sub wavelength light field confinement derived from the van der Waals heterostructures, may be an important step toward on-chip all-optical devices.Peer reviewe

Image_1_Genome-Wide Association Study of Haploid Male Fertility in Maize (Zea Mays L.).JPEG

<p>Large-scale application of the doubled haploid (DH) technology by in vivo haploid induction has greatly improved the efficiency of maize breeding. While the haploid induction rate and the efficiency of identifying haploid plants have greatly improved in recent years, the low efficiency of doubling of haploid plants has remained and currently presents the main limitation to maize DH line production. In this study, we aimed to assess the available genetic variation for haploid male fertility (HMF), i.e., the production of fertile pollen on haploid plants, and to investigate the underlying genetic architecture. To this end, a diversity panel of 481 maize inbred lines was crossed with “Mo17” and “Zheng58,” the F₁ hybrids subjected to haploid induction, and resulting haploid plants assessed for male fertility in two environments. Across both genetic backgrounds, we observed a large variation of HMF ranging from zero to ~60%, with a mean of 18%, and a heritability of 0.65. HMF was higher in the “Mo17” than in the “Zheng58” background and the correlation between both genetic backgrounds was 0.68. Genome-wide association mapping identified only few putative QTL that jointly explained 22.5% of the phenotypic variance. With the exception of one association explaining 11.77% of the phenotypic variance, all other putative QTL were of minor importance. A genome-wide prediction approach further corroborated the quantitative nature of HMF in maize. Analysis of the 14 significantly associated SNPs revealed several candidate genes. Collectively, our results illustrate the large variation of HMF that can be exploited for maize DH breeding. Owing to the apparent genetic complexity of this trait, this might best be achieved by rapid recurrent phenotypic selection coupled with marker-assisted selection for individual QTL.</p